In a striking about-face from just a few weeks ago, U.S. intelligence and Army officials now say they are cautiously optimistic about Pakistan's ability to fight its militants. The improved outlook reflects a series of developments, including both the Pakistani military campaign in the country's Swat Valley and shifting political currents that have prompted many Pakistanis to turn against extremist groups and back their government's anti-insurgency efforts. "All of a sudden military operations [against militants] are being imbued with a kind of legitimacy," said a senior U.S. intelligence official. Pakistan's operations in Swat and South Waziristan are already having a significant effect on the amount of arms and violence spilling over the border into Afghanistan."There's a definite impact, and I think it almost can't be overstated," said Col. John Spiszer, the commander for a unit than mans the Afghanistan-Pakistani border.